1. Field of the Invention
This invention relates to a jump rope device. Specifically, this invention relates to a jump rope structure having two ball chains, so that the rotational friction and drag during high-speed rope jumping can be significantly minimized.
2. Description of the Prior Art
A traditional jump rope mainly comprises a rope and a pair of handles. During a high-speed rope jumping, the handles held by a user do not rotate, but the rope is rotating. Under this circumstance, the rotational friction and drag are generated. These friction and drag not only damage the jump rope structure but also limit the maximum speed of rope jumping exercise.
Hence, a ball bearing attachment was invented to solve the above-mentioned problem. As shown in FIG. 1, it shows a ball-bearing swivel 80 (U.S. Pat. No. 2,466,243) for a jump rope structure. In which, a pair of ball bearing 81 is disposed inside. Each ball bearing 81 extends out a connecting ring 82 and further connects with a rope (not shown) or a handle (not shown). Therefore, when the rope is rotated at a high speed, the generated friction and drag will be absorbed by the low frictional ball bearing 81. Thus, the user can achieve a high-speed rope jumping exercise.
Another jump rope structure (U.S. Pat. No. 5,749,812) was invented later, as shown in FIG. 2. It comprises a pair of handles 91, a rope 92 and a pair of ball-bearing swivel 93. One end of the ball-bearing swivel 93 is disposed with a threaded portion 931. The other end of the ball-bearing swivel 93 is disposed with a rotatable spindle 932. Some portion of this rotatable spindle 932 extends out and connects with an O-ring 94 that is secured on one end of the rope 92. The handle 91 has a threaded hole 911 so as to fix with the threaded portion 931. Similarly, the ball-bearing swivel 931 basically can be rotated freely (over 360 degree). It also can reduce the rotational friction and drag between the rope 92 and the handle 91.
The primary object of the present invention is to provide a jump rope utilizing the unique ball chain design so that the rotational friction and drag during high-speed rope jumping can be significantly minimized
The second object of the present invention is to provide a jump rope device that is different to the existing patented structures.